Correction to: Inhaled gold nanoparticles cause cerebral edema and upregulate endothelial aquaporin 1 expression, involving caveolin 1 dependent repression of extracellular regulated protein kinase activity

It was highlighted that the original article [1] contained the wrong Fig. 1.

Inhaled gold nanoparticles cause cerebral edema and upregulate endothelial aquaporin 1 expression, involving caveolin 1 dependent repression of extracellular regulated protein kinase activity

Background

Gold nanoparticles (Au-NPs) have extensive applications in electronics and biomedicine, resulting in increased exposure and prompting safety concerns for human health. After absorption, nanoparticles enter circulation and effect endothelial cells. We previously showed that exposure to Au-NPs (40–50 nm) collapsed endothelial tight junctions and increased their paracellular permeability. Inhaled nanoparticles have gained significant attention due to their biodistribution in the brain; however, little is known regarding their role in cerebral edema. The present study investigated the expression of aquaporin 1 (AQP1) in the cerebral endothelial cell line, bEnd.3, stimulated by Au-NPs.

Results

We found that treatment with Au-NPs induced AQP1 expression and increased endothelial permeability to water. Au-NP exposure rapidly boosted the phosphorylation levels of focal adhesion kinase (FAK) and AKT, increased the accumulation of caveolin 1 (Cav1), and reduced the activity of extracellular regulated protein kinases (ERK). The inhibition of AKT (GDC-0068) or FAK (PF-573228) not only rescued ERK activity but also prevented AQP1 induction, whereas Au-NP-mediated Cav1 accumulation remained unaltered. Neither these signaling molecules nor AQP1 expression responded to Au-NPs while Cav1 was silenced. Inhibition of ERK activity (U0126) remarkably enhanced Cav1 and AQP1 expression in bEnd.3 cells. These data demonstrate that Au-NP-mediated AQP1 induction is Cav1 dependent, but requires the repression on ERK activity. Mice receiving intranasally administered Au-NPs displayed cerebral edema, significantly augmented AQP1 protein levels; furthermore, mild focal lesions were observed in the cerebral parenchyma.

Conclusions

These data suggest that the subacute exposure of nanoparticles might induce cerebral edema, involving the Cav1 dependent accumulation on endothelial AQP1.

Sustained cytokine production and immunophenotypic changes in human neuroblastoma cell lines transduced with a human gamma interferon vector

The majority of human neuroblastomas express low to undetectable levels of major histocompatibility complex (MHC) class I and II antigens (MHC-I and -II). We studied the effects of gamma interferon (gamma-IFN) transduction on expression of these antigens in six human neuroblastoma cell lines with and without genomic amplification of the N-myc oncogene. All six were stably transduced with an MoMLV-based gamma-IFN retroviral vector (DAh gamma-IFN). G418-resistant cells were assayed for MHC-I, MHC-II, B7-1, and neuroblastoma-associated antigen expression, as well as for gamma-IFN levels in cell culture supernatants. Sustained gamma-IFN production, 2 to > 1000 units/10(6) cells/d, was attained for five of six transduced cell lines and persisted for up to 9 months. This resulted in marked upregulation of MHC-I and MHC-II expression in LA-N-1, LA-N-6, and CHLA-127 cells and moderate upregulation in SK-N-Fi and SK-N-AS cells. One cell line (LA-N-1) had marked induction of MHC-I and MHC-II despite marginal levels of gamma-IFN production. Expression of CD28 ligand B7-1 (as determined by BB1 antibody) remained unchanged in all gamma-IFN-transduced cell lines tested. Expression of several neuroblastoma-associated antigens (NKH1A, 126-4, HSAN 1.2, HNK, 459, and 390) was upregulated in some of the gamma-IFN-transduced cell lines. These results demonstrate that preparation of gamma-IFN expressing neuroblastoma cells for immunotherapeutic purposes is feasible and that gamma-IFN transduction results in phenotypic changes that may improve immunogenicity of human neuroblastoma cells.